{"draft":"draft-despres-6a44-02","doc_id":"RFC6751","title":"Native IPv6 behind IPv4-to-IPv4 NAT Customer Premises Equipment (6a44)","authors":["R. Despres, Ed.","B. Carpenter","D. Wing","S. Jiang"],"format":["ASCII","HTML"],"page_count":"33","pub_status":"EXPERIMENTAL","status":"EXPERIMENTAL","source":"INDEPENDENT","abstract":"In customer sites having IPv4-only Customer Premises Equipment (CPE),\r\nTeredo (RFC 4380, RFC 5991, RFC 6081) provides last-resort IPv6\r\nconnectivity.  However, because it is designed to work without the\r\ninvolvement of Internet Service Providers, it has significant\r\nlimitations (connectivity between IPv6 native addresses and Teredo\r\naddresses is uncertain; connectivity between Teredo addresses fails\r\nfor some combinations of NAT types).  6a44 is a complementary\r\nsolution that, being based on ISP cooperation, avoids these\r\nlimitations.  At the beginning of 6a44 IPv6 addresses, it replaces\r\nthe Teredo well-known prefix, present at the beginning of Teredo IPv6\r\naddresses, with network-specific \/48 prefixes assigned by local ISPs\r\n(an evolution similar to that from 6to4 to 6rd (IPv6 Rapid Deployment\r\non IPv4 Infrastructures)).  The specification is expected to be\r\ncomplete enough for running code to be independently written and the\r\nsolution to be incrementally deployed and used.  This document defines\r\nan Experimental Protocol for the Internet community.","pub_date":"October 2012","keywords":["Coexistence","Transition","Interworking","Tunneling","Encapsulation","Mapping","map-and-encap","Global Addressing"],"obsoletes":[],"obsoleted_by":[],"updates":[],"updated_by":[],"see_also":[],"doi":"10.17487\/RFC6751","errata_url":"https:\/\/www.rfc-editor.org\/errata\/rfc6751"}